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Influence of incorporated nanodiamond particles on mechanical properties of composite material based on multi-layer PVA nanofiber textiles
Prošek, Zdeněk; Indrová, K.; Rácová, Z.; Ryparová, Pavla; Nežerka, V.; Topič, J.; Tesárek, Pavel; Kromka, Alexander
2015 - English
The present study investigates the influence of NDP on mechanical properties of multi-layer PVA nanofiber textiles. The particles of a diameter equal to 5 nm were incorporated into double- and triple-layer textiles, while the single-layer samples were prepared as the reference. The diameter of PVA nanofibers varied from 100 to 300 nm. We characterized the tensile strength, stiffness and ductility of fabricated nanofibers by using a conventional method – a tensile test. We found that the NDP-enriched nanofibers reveal antibacterial character. However, none or negligible influence of NDP additions on the tested mechanical properties was observed.
Keywords:
nanofibers; PVA; nanodiamonds; electrospinning; mechanical properties; SEM
Available at various institutes of the ASCR
Influence of incorporated nanodiamond particles on mechanical properties of composite material based on multi-layer PVA nanofiber textiles
The present study investigates the influence of NDP on mechanical properties of multi-layer PVA nanofiber textiles. The particles of a diameter equal to 5 nm were incorporated into double- and ...
Fabrication of 3D diamond membranes for microfluidic systems
Varga, Marián; Babchenko, Oleg; Bauerová, Pavla; Hruška, Karel; Jurka, Vlastimil; Kromka, Alexander; Rezek, Bohuslav
2015 - English
Perfusion of cell medium, especially in microfluidic devices, can provide in-vivo-like conditions for cell cultures. The most recent demand on such systems is to include electronically active artificial cell support for in-situ monitoring. Diamond thin films exhibit advantageous combination of physical, mechanical, chemical, biocompatible and electronic properties for this purpose. In this work we explore two strategies for fabrication of self-standing three-dimensional nanocrystalline diamond membrane for implementation in microfluidic invivo like experiments: i) nucleation and chemical vapour deposition (CVD) growth of diamond on porous 3D carbon foam (with 80 pores per inch) and ii) selective diamond growth predefined by photolithographic processing using copper grid mask. The morphology and material quality of the fabricated membranes are characterized by scanning electron microscopy and Raman spectroscopy.
Keywords:
nanocrystalline diamond; membranes; microwave plasma; microfluidics; carbon foam
Available at various institutes of the ASCR
Fabrication of 3D diamond membranes for microfluidic systems
Perfusion of cell medium, especially in microfluidic devices, can provide in-vivo-like conditions for cell cultures. The most recent demand on such systems is to include electronically active ...
(100) substrate processing optimization for fabrication of smooth boron doped epitaxial diamond layer by PE CVD
Mortet, Vincent; Fekete, Ladislav; Ashcheulov, Petr; Taylor, Andrew; Hubík, Pavel; Trémouilles, D.; Bedel-Pereira, E.
2015 - English
Boron doped diamond layers were grown in an SEKI AX5010 microwave plasma enhanced chemical vapour deposition system. Effect of surface preparation, i.e. polishing and O2/H2 plasma etching on epitaxial growth on type Ib (100) HPHT synthetic diamonds were investigated. Using optimized substrate preparation, smooth (RRMS ~ 1 nm) boron doped diamond layers with metallic conduction and free of un-epitaxial crystallites were grown with a relatively high growth rate of 3.7 μm/h. Diamond were characterized by optical microscopy, optical profilometry, atomic force microscopy and Hall effect.
Keywords:
doping; PE CVD; diamond; surface treatment; thin film
Available at various institutes of the ASCR
(100) substrate processing optimization for fabrication of smooth boron doped epitaxial diamond layer by PE CVD
Boron doped diamond layers were grown in an SEKI AX5010 microwave plasma enhanced chemical vapour deposition system. Effect of surface preparation, i.e. polishing and O2/H2 plasma etching on epitaxial ...
Doped DLC coatings for biomedical applications
Písařík, Petr
2015 - English
Nowadays there are materials having excellent properties for use in medicine (Diamond-like carbon, Hydroxyapatite, …). Diamond-like carbon (DLC) is a metastable form of amorphous carbon containing bonded carbon atoms of sp2 and sp3 hybridized orbital. DLC layers are semiconductors with high mechanical hardness, chemical inertness, low coefficient of friction, high thermal conductivity, good electrical and optical properties, biocompatibility and no cytotoxicity. All properties of the films are not always ideal, so it is necessary to modify the layer. One example of how to modify the properties of thin layers are dopations. The incorporation of dopants in films may lead to greater multifunctionality and much improved properties. Most modifications were made to modify contact angle and surface energy, to reduce internal stresses, to decrease surface roughness, coefficient of friction or wear....
Keywords:
silver doped; diamond like carbon; thin layers; mechanical properties
Available at various institutes of the ASCR
Doped DLC coatings for biomedical applications
Nowadays there are materials having excellent properties for use in medicine (Diamond-like carbon, Hydroxyapatite, …). Diamond-like carbon (DLC) is a metastable form of amorphous carbon containing ...
Initial study of structure of nanofiber textiles and the creation of its model
Havrlík, M.; Sveshnikov, Alexey
2015 - English
In this research, the structure of the fabrics was analyzed using an electron scanning microscope Tescan Maia 3. Two sets of the experiments have been carried out. In the first experiment the surface structure of the samples was studied. Photos created by SEM were analyzed using program Atlas and image editor GIMP. In this set of the experiments the initial parameters for the creation of a digital 2D model of a single layer have been determined (fiber size distribution, pore size and curvature of the fibers). In the second set of the experiments cross sections of nanofiber textiles were made in order to study the inner structure of the fabric. This information allows evaluation of the total number of 2D layers in the model and, thus, is very important for future creation of a 3D model of the fabric.
Keywords:
polymer; SEM photography
Available at various institutes of the ASCR
Initial study of structure of nanofiber textiles and the creation of its model
In this research, the structure of the fabrics was analyzed using an electron scanning microscope Tescan Maia 3. Two sets of the experiments have been carried out. In the first experiment the surface ...
Nanomechanical testing of an a-C:N nanolayer prepared by ion beam assisted deposition on Ti.sub.6./sub.Al.sub.4./sub.V alloy
Vlčák, P.; Šepitka, J.; Horaždovský, T.; Jirka, Ivan; Gregora, Ivan; Němec, M.
2015 - English
We applied ion beam assisted deposition for preparing a-C:N nanolayers on Ti6Al4V alloy. A Hysitron TI 950 TriboIndenter (TM) nanomechanical test instrument was used to assess the depth profiles of the mechanical properties on modified titanium substrates. Two methods were employed : a) quasistatic partial unload, and b) dynamic Continuous Measurement of X (CMX). The average nanoindentation hardness increased from HIT similar to 5GPa for a reference sample to HIT similar to 8.6 GPa for a sample coated by an a-C nanolayer, and to HIT similar to 11.5 GPa for a sample coated by an a-C:N nanolayer. The average storage modulus of the sample coated by a-C:N increased from E' similar to 130 GPa (reference sample) to E' similar to 155 GPa. The storage modulus of the sample coated by the a-C nanolayer was less than the storage modulus of the titanium substrate.
Keywords:
carbon-based materials; hardness; ion beam assisted deposition; a-C:N nanolayer
Available at various institutes of the ASCR
Nanomechanical testing of an a-C:N nanolayer prepared by ion beam assisted deposition on Ti.sub.6./sub.Al.sub.4./sub.V alloy
We applied ion beam assisted deposition for preparing a-C:N nanolayers on Ti6Al4V alloy. A Hysitron TI 950 TriboIndenter (TM) nanomechanical test instrument was used to assess the depth profiles of ...
Computational study of cellular assembly on hydrophobic/hydrophilic micro-patterns
Ukraintsev, Egor; Brož, A.; Kalbáčová, M.H.; Kromka, Alexander; Rezek, Bohuslav
2015 - English
We develop simple onedimensional stochastic model of cell behavior on chemically patterned surfaces that is based on three key parameters: speed of cell movement (motility) across substrate, probability of cell adhesion to substrate, and probability of cell division on substrate when adhered on substrate. Amount of adhered cells on hydrophobic and hydrophilic regions is calculated as function of time (number of cycles up to 2000). The model is correlated with in-vitro data obtained within 48 h in real time. We show that this simple stochastic model with the three parameters (where cell motility is the most important one) can describe with high accuracy the experimental data and thereby explain the observed preferential cell assembly on hydrophilic/hydrophobic micro-patterns (up to 200 um width).
Keywords:
SAOS-2 cells; cell movement; adhesion; stochastic computer simulations
Available at various institutes of the ASCR
Computational study of cellular assembly on hydrophobic/hydrophilic micro-patterns
We develop simple onedimensional stochastic model of cell behavior on chemically patterned surfaces that is based on three key parameters: speed of cell movement (motility) across substrate, ...
Hydrogen-terminated diamond surface as gas sensing layer working at room temperature
Davydova, Marina; Kulha, P.; Babchenko, Oleg; Kromka, Alexander
2015 - English
Effect of fluorine- and hydrogen-terminated diamond surface on the gas sensing properties at room temperature was investigated. The gas sensing properties diamond-based sensor were measured by the changes of electrical resistance to various volatile organic compounds (C6H6, C3H6O, isopropylalcohol) and relative humidity. The comparative sensing performance of hydrogenated diamond surface shows improvement in sensitivity toward benzene, acetone, isopropylalcohol and humid air in contrast to fluorinated diamond surface, where the surface conductivity was suppressed.
Keywords:
diamond; gas sensor; response; sensitivity
Available at various institutes of the ASCR
Hydrogen-terminated diamond surface as gas sensing layer working at room temperature
Effect of fluorine- and hydrogen-terminated diamond surface on the gas sensing properties at room temperature was investigated. The gas sensing properties diamond-based sensor were measured by the ...
Growth of Escherichia coli on nanocrystalline diamond
Jurková, Blanka; Kozak, Halyna; Artemenko, Anna; Ukraintsev, Egor; Beranová, J.; Konopásek, I.; Kromka, Alexander
2015 - English
In this contribution, we compared the attachment of gram-negative model bacterium Escherichia coli to\nuncoated glass and glass coated by hydrogenated and oxidized NCD films. For attachment experiments,\ncontinuous cultivation in commercially available CDC Bioreactor was used. Antibacterial tests indicated\nhigher attachment of gram-negative model bacterium Escherichia coli to NCD surface compared to uncoated\nglass. We assign this effect to higher roughness of NCD surface compared to glass. Bacterial cells preferred\nthe hydrophobic surface of hydrogenated NCD surface to hydrophilic oxidized NCD for their attachment.
Keywords:
nanocrystalline diamond; bacteria; Escherichia coli; anti-adhesive; CDC Bioreactor
Available at various institutes of the ASCR
Growth of Escherichia coli on nanocrystalline diamond
In this contribution, we compared the attachment of gram-negative model bacterium Escherichia coli to\nuncoated glass and glass coated by hydrogenated and oxidized NCD films. For attachment ...
Calculations of nanocrystalline diamond-covered waveguides based on amorphous silicon
Jirásek, Vít; Prajzler, Václav; Remeš, Zdeněk
2015 - English
Nanocrystalline diamond (NCD) coatings on planar waveguides (WG) in the IR region allow to design optical sensors sensitive to absorbers like proteins or other biomolecules. In this contribution, we present a 2D model of a multi-layer WG developed under FEM (finite element method) simulation software Comsol Multiphysics. The model is based on the modified wave equation solved in the frequency domain and includes optical absorption. It was found that for the single-mode WG working in the narrow region of 1550-2000 nm the silicon thickness must be 150-320 nm. It was found that in order to keep a reasonable signal attenuation, the NCD film must be prepared with the optical absorption coefficient lower than 10 cm-1, being a rather challenging task. Dependencies of the signal attenuation on the NCD film thickness, absorbing layer height, its absorption coefficient and exciting wavelengths are presented.\n
Keywords:
nanocrystalline diamond; amorphous silicon; optical waveguides; FEM simulations
Available at various institutes of the ASCR
Calculations of nanocrystalline diamond-covered waveguides based on amorphous silicon
Nanocrystalline diamond (NCD) coatings on planar waveguides (WG) in the IR region allow to design optical sensors sensitive to absorbers like proteins or other biomolecules. In this contribution, we ...
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